Multiple-unit boiler



sept. 9, 1930. w, R, WOOD 1,775,336

MULTI PLE UNIT BOILER Fil'ed Nov. 26, 192e v 3 sheets-sheet 1 ff?V Z0 EQZMQE" KM/E) VE 0R W Nm/ f" WiL/@M ATTORNEYS sept. 9, 1930. w. R. WOQD 1,775,336

MULTIPLE UNIT BOILER Filed Nov. 26, 1926 3 Sheets-Sheet 2 INVEN 0R BY W1 fr? WML A TTORNEY Sept. 9, 1930. I w, R. WOOD MULTIPLE UNIT BOILER Filed Nov. 26, 1926 3 Sheets-Sheet 3 oooooooo OOOOOOOOOOO OOOOOOOO INVEN 0R BY ya f, M51@ A TT ORNE K9 patent/ed Sept. 9, 1930 UNITED sTATEs PATENT OFFICE WEFRED B. WOOD, LONDON, ENGLAND, ASSIGNOR T0 INTERNATIONAL COMBUSTION ENGINEERING CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE MULTIPLE-UNIT BOILER l r Appli'v tion led November 26, 1926, Serial No. 150,697, and in Great Britain December 10, 1925.

This invention relates to steam enerators of a type similar to that illustrate in my copending application, Serial No. 3,921, filed January 22, 1925, patented Nov. 19, 1929,

Patent No. 1,736,423."

It is one of the primary obj ects of m invention to provide a steam generator ma e up oi a numberof 'smaller units of standard design, so that a generator of large or small size and capacity may be made up of an assembly of any desired number of units without the necessity of having new designs for each installation'. The various parts which goto make up neach individual unit. e. g., tubes, headers, drums, etc., are also, for the most part, of standard size and shape, and each individual unit will, therefore, be easily and cheaply assembled.

It is a further object of my invention to provide a steam generator wherein a number of generator units may be placed in one setting, thus obviating the need of many parts 4and much construction which would be required if each unit were placed in an individual setting. .Y

A still further object of the invention lies in the provision of a furnace shaped boiler constructed with one or more partitions, so that the interior of the furnace is divided into a plurality of combustion chambers, each of which is of a Vcapacity suitable for being fired, preferably in the tumultuous or turbu lent manner described in my copending ap-V plication above referredl to.

It is a further object of my invention to provide, in a steam generator, a combustion space beyond the boiler .elements proper, with means for utilizing the heat generated therein in the operationof the generator.

How the foregoing, together with such other lobjects. as may hereinafter appear, or are incident to my invention, are realized is illustrated in preferred form in the accompanying drawings, wherein- Fig. lis a sectional elevation of a steam generator embodying my improveniente.'l

Fig. 2 is a section taken substantial/ly on the line 2`2 of Fig. 1. l

Fig. 3 illustratesv a modiiied arrangement of boiler elements, and is more or less diagrammat1c.

Fig. 4 is a fragmentary plan section taken on the line 4 4 of Fig'. 3.

Referring now to Figs. 1 and 2, the combustion chamber, as a whole, is indicated by the reference letter A. This large chamber A' is composed of four smaller combustion chambers B in the form of steam generator illustrated. The buckstays 6 support the cross beams 7 from which the upper drums 8 aresuspendedbymeans of the straps 9. Rows of vertical finned tubes 10 connect the upper of combustion. These tubesY 14 define the bottom of the combustion space.

Two rows of tubes 15 extend vertically upward from the drum 13 to headers, and are connected at their upper ends into headers 16 which are, in turn, connected into the/drums 8 by means o'f the single rows of tubes 17 which define the top of the combustion space.

i It will be seen that the-tubes 15 form, in effect, a partition in the large combustion chamber A dividing it lengthwise into two smaller combustion chambers, each of which is further divided by means of the rows of vertical finned tubes 18 connected at the top into headers 19 extending at right angles to, and in turn connected to the drums 8. At

enl

their lower ends the tubes 18 are connected to the headers 20 which are connected into the drums 13 by means of the T 21. These chamber `A are delined by rows :of finned 10b tubes connected similarly to the tubes 18 into lower headers which lead tothe drum 13 and into upper-headers 22 (see F1g..2) whlch are connected to the drums 8.

A refractory sheathing 24, similar to the f sheathing 12, covers the tubes defining the en'ds of the combustion ichamber.

The tubes 17 support the refractory roof 23 of the combustion chamber A. Downf comers 41, outside the endsI of the combustion chamber A, connect drums 8 with drums 13.

It will be observed that the headers 19 and 22 extend above the roof 23, and the lower headers 2O lie below the bottom of the combustion chamber A, and these headers are, therefore, protected from the heat of the combustion chamber in a very simple and inexpensive manner, and without the necessity o'fdbending the tubes to get the headers outs1 e.

Pulverized coal is supplied from bins 25 by means of feeders 26 to the lines 27 which lead to distributor boxes 28. Air to carry the coal is supplied by blower 29.

There are twopulverized fuel burners 30 at each corner of each of the smaller combustion chambers B, which are connected to the l distributors 28 by means of the pipes 31.

The settling chamber F lies below and is common to all four of the combustion chambers B. The oitake C leads from the settling chamber, and is,therefore, the common otake for the chambers B. Y

The steam superheater D is located in the offtake. andthe air heater E is connected to the offtake just beyond the superheater D.

The blower 33 is connected to the air heater E and draws the gaseous products of combustion through it where the heat of these gases is imparted to the air which is forced through the heater by means of the blower 34.

The heated air passes from the lower end of the heater into the conduit 34 which has branches 35 leading to the burners atthe sides and corners of the combustion chamber A. The four sets of burners in the center of the combustion chamber A are supplied by means of branches 36 leading to the air box 37 which extends down into the combustion chamber.

There is also a branch 38 leading from the conduit 34 to the blower 29 by means of which heated air is supplied for transportation of the fuel. The branch 38 is controlled by damper 39 which regulates theamount of air in accordance with the rating at which n the furnace is being run. Cooler air for dilution may be supplied by means of pipe 40, if desired.

The burners 30 are set to deliver the fuel and air into cach combustion chamber B in a stream, the direction of which is substantially tangential to the circle indicated at the cen- -ter of the chamberl (see Fig. 4). The main portion of the preheated air is blown into the tubes.

nected at the top into headers 44 which are connected to drum 42 by means of tubes 17 row of tubes 15', extending fromV the 'drum 42 to lower header 45, forms a. partition lengthwise of the combustion chamber. Header 45 is connected to drums 43 by means of `tubes 14. Upper headers 22 are connected to and extend at right angles from drum 42 near each end thereof, and rows of vertical finned tubes 18 are connected at the top into these headers 22 andat the bottom into corresponding headers which are, in turn, connected to drums 43. Headers 20 and vertical tubes are connected in like manner to the drums at the center, and form a partition which further divides the combustion chamber into four smaller chambers.

The downcomers 41 connect drum 42 with drums 43.

that I have provided multiple boilers ar- -ranged in the same general setting, which, of

itself, tends to reduce size, number of parts, and cost. In the next place, it will be noted that each boiler is comprised of more or less standard parts from which multiple boiler arrangements may be constructed with a minimum number of parts which might be termed special parts, the size vand dimensions of which will vary with ,the number of boiler units in the particular installation.

The standardization of parts tends to reduce cost. Furthermore, certain parts are common which tends to reduce cost. In addition to the foregoing, the boilers are primarily of the radiant heat type, and, consequently, may be made of relatively smaller size and may be made with less number of parts than the ordina-ry boiler, and such radiant heat type ofboiler lends itself most readily to the construction of a multiple unit boiler, making it possible to realize many of the advantages above set forth.

In so far as circulation is concerned, it will be seen that in all forms the downcomers lead from the high point to the low point of the boiler units, the circulation in the parts delining the combustion chambers being upward and very rapid by reason of the employment of so many upright tubes.

If the boiler units are designed of a size such as to have capacity to supply all demands eiiiclentlyfrom the standpoint of combustion ofthe fuel, substantially all of the air required for combustion will bc admitted into the combustion 'space or spaces defined by the If, however, it is desired to still further decrease the size ofthe boilers-which is desirable-I propose decreasing the evaporating area of the boiler units, and, consequently, the size of the combustion spaces defined by the units to the point where each unit will have capacity to meet only .normal demands efficiently. Such a boiler is desirable from the standpoint of smallness of size', and, consequently', plant investment. Tol make such a boiler meet peak load demands, I intentionally operate it, during peak load periods, inefficiently from a combustion standpoint, but with a higher flame temperature, so as to increase the rate of heat transfer, and thus develop the capacity required for peak demands. To this end, during peak periods, I increase therate of feed of fuel to the desired point, but admit a deficiency of air for lcombustion in the 'combustion space defined by' the boiler, intentionally operating to obtain very high CO2 percentage and consequent high flame temperature.

Under such conditions of operation, thereI will be combustibles in the gases leaving the combustion spaces defined by thev boiler, and I, therefore, admitl the ladditional -air required for combustion to the settling chamber F which isu provided with damper crtconsumed before the gases lreach any of the economizer devices located inv the oftake.

Any increase in. temperature of the gases leaving the boiler will not necessarily manifest itself in any unduly high temperature of the final exit gases because, at 'times of peakp demands, there are larger quantities of steam flowing through the superh'eater elements and larger quantities of combustion air flowing through the air heater, and, therefore,

more heat units are required inthe offtake to heat the larger quantities-of steam and air. y

The preheated combustion air) supplied same with each of the two lower drums and" defining the bottom of the combustion space,

split'thecombustion space into two inde-` pendent combustion spaces, together with an outlet chamber common to both said combustion spaces and an dfftake forthe wast-ev v gasesfrom said chamber.` '-2. In combmatlon, 1n a drums, two lower drums one under each of the upper drums, drumlike means located boiler, two upper substantially'midway.between and on a different level than the two upper drums, tubes leading fromthe said means to each upper.

drum and defining thetop of the combus tion space for the boiler, upright substan` tially vertical tubes connecting each pair of upper and lower drums and defining sides of the combustion space, drumlike means` located substantially midway of the lower drums andv on a different level,'tubes connecting the same with each of the two lower drums and defining the bottom of the combusti'on space., upright substantially vertical tubes definingv the remaining sides of the combustion space connected for circulation, and upright substantially vertical tubes connecting the intermediate drumlike means and operating` to split the combustion space into two independent combustion spaces, together with an outlet chamber common to both said combustion chambers and an offtake for the waste gases from said chamber and a superhea'ter located in said offtalre.

In testimony whereof I have hereunto signed my name. y v

` WILFRED R. WOOD.I

increases the temperature head in thecomp bustion space.

1. In combination, in a boiler, two upper drums, two lower drumsI one under each of theupper drums, drumlike means located 'substantially midway between and on 'a different level than the two upper drums,.tubes l leading from the said means to each upperv drum andi defining the top of the combustion space for the boiler, upright substantially avertical tubes connecting each pair of upper and lower drums and defining sides of the combustion space,` drumlike means located substantially midwa of the lower drums and on adierent leve tubes connecting the. 

